The TV only shows CC with an actual dvd & dvd player, TV does not show CC from iso from media players. (Dune, WD303tv, argosy, & now the Micca)
I have a lot of dvds ript to iso which with my computer (using WinDVD) which shows them, but I dont want to connect a computer to the TV.

Whats the deal with CC on dvds anyway? Why not just go with subtitles? It seems the majority of dvds use subtitles rather than CC.

It's a different format with (originally) a different purpose. SDH - Subs for Deaf & Hard of Hearing. And was meant & designed to work with SD material (first analog, then digital), commonly for Broadcast. See: https://www.3playmedia.com/2015/08/11/whats-the-difference-between-cea-608-line-21-cap...-708-captions/.
Files captured with merely 480 lines (NTSC) do NOT have line 21 (used in 608 type CCs), because line 21 was in one of those 3 top missing lines (the other 3 being at the bottom) - remember, pro SD capture cards cap to 486 lines.
And unless someone went to a lot of trouble converting MPEG2 aux user data streams (used in 708 type CCs), there won't be anything existing in MP4s, etc.

When ript (from dvd), the (which-ever) CC is included in the rip, iso/dvd folder. On computer I use 'WinDVD' software media player, & if CC's are there the option to view them is enabled. Which-ever, Sly/Red/DVDSmith is used to rip, the CCs are also ript to iso/folder. Cant they (hardware media players) program their firmware to access CC when it is present?

I ran bulldozers/loud heavy equipment for 40 years is why I need subtitles/CC!

The TV only shows CC with an actual dvd & dvd player, TV does not show CC from iso from media players. (Dune, WD303tv, argosy, & now the Micca)
I have a lot of dvds ript to iso which with my computer (using WinDVD) which shows them, but I dont want to connect a computer to the TV.

Whats the deal with CC on dvds anyway? Why not just go with subtitles? It seems the majority of dvds use subtitles rather than CC.

-corne-

As far as I know, only the only devices that were ever required by law to display closed captions are TVs, although ATSC DTA converter boxes, cable boxes/DVRs, and satellite receivers will either display closed captions themselves or supply them for the TV to decode when connected to a TV using a composite video connection or RF out.

Closed caption display by TVs only became a legal requirement in 1993, after the passage of the 1990 Americans with Disabilities Act, which means that the primary regulations governing closed caption display predate the availability of HDMI, media players, DVD players, and Blu-ray players to consumers. For that reason, media players (even those built into TVs), DVD players, and Blu-ray players are exempt from the ADA's closed captioning regulations to display closed captions if they are present, and SDH subtitles and 608/708 closed captions are completely optional on DVD and Blu-ray.

I have heard there are some Blu-ray players which can display closed captions on DVD and Blu-ray but this ability may not extend to media files. As Cornucopia wrote, closed captions are often not present in media files because re-encoding nearly always fails to preserve the closed captioning in the GOP user data. VideoReDo TV Suite V 5 is the only program that I know of which preserves closed caption data in the re-encoded video.

It is possible to turn broadcast CCs into srt subtitles with CCExtractor GUI, but I normally use an HTPC and VLC or NextPVR to watch media files with US broadcast closed captions.

The reason it works with those ISOs in WinDVD, PowerDVD, etc. is because:
1. the rip is a true whole rip, not a conversion. so it still has the CC data (embedded in the MPEG2 aux user data sections).
2. the app is designed to allow for CCs and create a subs-style overlay prior to sending out the video
3. they're trying to operate as if they were a hardware DVD player (which, if they are conscientious for the consumer, and well designed, would include CCs the same way)

General media players rarely use whole ISO rips, usually conversions.
Most conversions don't take into account the embedded CC data, so it is ignored/lost in the conversion.
Even if it's still there in the supported format, GM players rarely are designed to expect to see that material, or don't know where to look for it.
The only way it IS successful for the vast majority of GM players is if there is a side conversion strictly of the CC data into a subs-compatible format and that is later muxed into the MP4 or MKV, etc. as a sub. See what u_q mentioned.

CCExtractor GUI works reasonably well for creating SRT subtitles from standard closed captions but because SRT subtitles don't include a way to specify the location for the text, the positioning that is sometimes used to indicate who is speaking is lost. CC Extractor GUI includes a setting to deal with "roll-up" captions, but you may still have to do a lot of manual corrections for those.

The latest makemkv also added CC extraction if its present in the stream. Tried it on season 1 of star trek voyager (only has CC) and the output was good. The extractor in megui will also pull the closed captions if present from DVD sources to a SRT file. Only oddity is it sometimes saves to UTF-8 so I have to resave it manually or with batch subtitles converter to ANSI so my portable DVD player sees them.

I decided to look for some current model Blu-ray and UHD Blu-ray players which can display closed captions. I looked at LG because I like the LG Blu-ray player that my mother has, although unfortunately it doesn't include closed caption display, and would probably choose another LG to replace it.

These models can display closed captions on DVD, Blu-ray, and some media files according to the manuals:
LG UBK80
LG UBK90
LG BP175
LG BP350

I don't know if other makers include a closed-caption feature in any of their current model Blu-ray players.